Static mixers may be used to mix low viscosity fluid or fluids flowing in a pipe or conduit. Static mixers typically include an arrangement of fixed vanes or other elements that are mounted in a section of the conduit and arranged to impart turbulence to a fluid flowing in the conduit as the fluid flows around the vanes or other elements. Some static mixer designs may be relatively energy efficient in that they may impart the required amount of turbulence to fluid flow with a relatively small pressure drop in fluid flowing through the mixing elements. However, a disadvantage with such static mixers is that they may have long mixing lengths—they may require a significant amount of conduit length to effect a desired amount of mixing.
Other static mixer designs may provide “length efficient” mixing. This means that the static mixer effects a desired amount of mixing at a relatively short distance downstream of the static mixer. However, such static mixers may possess a disadvantage in that they may use more energy to effect the desired amount of mixing, which results in a higher pressure drop in the fluid flowing across the mixer. Accordingly, there is a need for a static mixer that provides thorough mixing of the fluids in the conduit in which it is mounted in a relatively short distance and at a pressure drop that may be relatively small compared to static mixers of comparable size and mixing effect.
Static mixers may be used to mix fluids having different physical properties, such as different viscosities. Such differences in physical properties may require the use of static mixers that are relatively long in comparison to the diameter of the conduit in which they are mounted, or which may require relatively long mixing distances. In some applications, it may be necessary to use multiple static mixer elements, arranged serially in a conduit. Accordingly, there is a need for a static mixer that is capable of mixing fluids having different physical properties, but is of a relatively short length, does not require a significant mixing distance downstream of the mixing element, and which can affect the desired amount of mixing with a single mixer element.